scripts: Dropped list/tuple distinction in Rbyd.fetch
Also tweaked how we fetch shrubs, adding Rbyd.fetchshrub and Btree.fetchshrub instead of overloading the bd argument. Oh, and also added --trunk to dbgmtree.py and dbglfs.py. Actually _using_ --trunk isn't advised, since it will probably just result in a corrupted filesystem, but these scripts are for accessing things that aren't normally allowed anyways. The reason for dropping the list/tuple distinction is because it was a big ugly hack, unpythonic, and likely to catch users (and myself) by surprise. Now, Rbyd.fetch and friends always require separate block/trunk arguments, and the exercise of deciding which trunk to use is left up to the caller.
This commit is contained in:
Christopher Haster
+73
-65
@@ -90,10 +90,10 @@ def bdgeom(s):
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return int(s, b)
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# parse some rbyd addr encodings
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# 0xa -> [0xa]
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# 0xa.c -> [(0xa, 0xc)]
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# 0x{a,b} -> [0xa, 0xb]
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# 0x{a,b}.c -> [(0xa, 0xc), (0xb, 0xc)]
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# 0xa -> (0xa,)
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# 0xa.c -> ((0xa, 0xc),)
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# 0x{a,b} -> (0xa, 0xb)
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# 0x{a,b}.c -> ((0xa, 0xc), (0xb, 0xc))
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def rbydaddr(s):
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s = s.strip()
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b = 10
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@@ -124,7 +124,7 @@ def rbydaddr(s):
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else:
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addr.append(int(s, b))
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return addr
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return tuple(addr)
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def crc32c(data, crc=0):
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crc ^= 0xffffffff
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@@ -439,9 +439,9 @@ class Rattr:
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self.tag = tag
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self.weight = weight
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if isinstance(blocks, int):
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self.blocks = [blocks]
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self.blocks = (blocks,)
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else:
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self.blocks = list(blocks)
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self.blocks = blocks
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self.toff = toff
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self.tdata = tdata
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self.data = data
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@@ -515,9 +515,9 @@ class Ralt:
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self.tag = tag
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self.weight = weight
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if isinstance(blocks, int):
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self.blocks = [blocks]
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self.blocks = (blocks,)
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else:
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self.blocks = list(blocks)
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self.blocks = blocks
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self.toff = toff
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self.tdata = tdata
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self.jump = jump
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@@ -570,9 +570,9 @@ class Rbyd:
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gcksumdelta=None,
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corrupt=False):
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if isinstance(blocks, int):
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self.blocks = [blocks]
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self.blocks = (blocks,)
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else:
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self.blocks = list(blocks)
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self.blocks = blocks
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self.trunk = trunk
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self.weight = weight
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self.rev = rev
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@@ -615,51 +615,7 @@ class Rbyd:
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return hash((frozenset(self.blocks), self.trunk))
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@classmethod
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def fetch(cls, bd, blocks, trunk=None):
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# multiple blocks? unfortunately this must be a list
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if isinstance(blocks, list):
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# fetch all blocks
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rbyds = [cls.fetch(bd, block, trunk) for block in blocks]
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# determine most recent revision
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i = 0
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for i_, rbyd in enumerate(rbyds):
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# compare with sequence arithmetic
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if rbyd and (
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not rbyds[i]
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or not ((rbyd.rev - rbyds[i].rev) & 0x80000000)
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or (rbyd.rev == rbyds[i].rev
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and rbyd.trunk > rbyds[i].trunk)):
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i = i_
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# keep track of the other blocks
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rbyd = rbyds[i]
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rbyd.blocks += tuple(
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rbyds[(i+1+j) % len(rbyds)].block
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for j in range(len(rbyds)-1))
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# and patch the gcksumdelta if we have one
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if rbyd.gcksumdelta is not None:
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rbyd.gcksumdelta.blocks = rbyd.blocks
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return rbyd
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block = blocks
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# blocks may also encode trunks
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block, trunk = (
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block[0] if isinstance(block, tuple)
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else block,
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trunk if trunk is not None
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else block[1] if isinstance(block, tuple)
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else None)
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# bd can be either a bd reference or a preread block
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#
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# preread blocks can be useful for avoiding race conditions
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# with cksums and shrubs
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if isinstance(bd, Bd):
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# seek/read the block
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data = bd.readblock(block)
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else:
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data = bd
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def _fetch(cls, data, block, trunk=None):
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# fetch the rbyd
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rev = fromle32(data[0:4])
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cksum = 0
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@@ -756,6 +712,39 @@ class Rbyd:
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gcksumdelta=gcksumdelta,
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corrupt=not trunk_)
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@classmethod
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def fetch(cls, bd, blocks, trunk=None):
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# multiple blocks?
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if not isinstance(blocks, int):
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# fetch all blocks
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rbyds = [cls.fetch(bd, block, trunk) for block in blocks]
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# determine most recent revision
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i = 0
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for i_, rbyd in enumerate(rbyds):
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# compare with sequence arithmetic
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if rbyd and (
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not rbyds[i]
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or not ((rbyd.rev - rbyds[i].rev) & 0x80000000)
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or (rbyd.rev == rbyds[i].rev
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and rbyd.trunk > rbyds[i].trunk)):
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i = i_
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# keep track of the other blocks
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rbyd = rbyds[i]
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rbyd.blocks += tuple(
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rbyds[(i+1+j) % len(rbyds)].block
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for j in range(len(rbyds)-1))
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# and patch the gcksumdelta if we have one
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if rbyd.gcksumdelta is not None:
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rbyd.gcksumdelta.blocks = rbyd.blocks
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return rbyd
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# seek/read the block
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block = blocks
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data = bd.readblock(block)
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# fetch the rbyd
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return cls._fetch(data, block, trunk)
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@classmethod
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def fetchck(cls, bd, blocks, trunk, weight, cksum):
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# try to fetch the rbyd normally
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@@ -772,6 +761,15 @@ class Rbyd:
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return rbyd
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@classmethod
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def fetchshrub(cls, rbyd, trunk):
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# steal the original rbyd's data
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#
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# this helps avoid race conditions with cksums and stuff
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shrub = cls._fetch(rbyd.data, rbyd.block, trunk)
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shrub.blocks = rbyd.blocks
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return shrub
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def lookupnext(self, rid, tag=None, *,
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path=False):
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if not self or rid >= self.weight:
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@@ -1516,9 +1514,9 @@ def dbg_tree(rbyd, *,
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def main(disk, blocks=None, *,
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trunk=None,
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block_size=None,
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block_count=None,
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trunk=None,
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color='auto',
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**args):
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# figure out what color should be
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@@ -1536,9 +1534,19 @@ def main(disk, blocks=None, *,
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block_count = block_count_
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# flatten blocks, default to block 0
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if not blocks:
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blocks = [(0,)]
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blocks = [block for blocks_ in blocks for block in blocks_]
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blocks = list(it.chain.from_iterable(blocks)) if blocks else [0]
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# blocks may also encode trunks
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blocks, trunk = (
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[block[0] if isinstance(block, tuple)
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else block
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for block in blocks],
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trunk if trunk is not None
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else ft.reduce(
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lambda x, y: y,
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(block[1] for block in blocks
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if isinstance(block, tuple)),
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None))
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with open(disk, 'rb') as f:
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# if block_size is omitted, assume the block device is one big block
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@@ -1548,7 +1556,7 @@ def main(disk, blocks=None, *,
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# fetch the rbyd
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bd = Bd(f, block_size, block_count)
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rbyd = Rbyd.fetch(bd, blocks)
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rbyd = Rbyd.fetch(bd, blocks, trunk)
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# print some information about the rbyd
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print('rbyd %s w%d, rev %08x, size %d, cksum %08x' % (
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@@ -1587,6 +1595,10 @@ if __name__ == "__main__":
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nargs='*',
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type=rbydaddr,
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help="Block address of metadata blocks.")
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parser.add_argument(
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'--trunk',
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type=lambda x: int(x, 0),
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help="Use this offset as the trunk of the tree.")
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parser.add_argument(
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'-b', '--block-size',
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type=bdgeom,
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@@ -1595,10 +1607,6 @@ if __name__ == "__main__":
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'--block-count',
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type=lambda x: int(x, 0),
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help="Block count in blocks.")
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parser.add_argument(
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'--trunk',
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type=lambda x: int(x, 0),
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help="Use this offset as the trunk of the tree.")
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parser.add_argument(
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'--color',
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choices=['never', 'always', 'auto'],
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